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C# List of objects, how do I get the sum of a property
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And if you need to do it on items that match a specific condition...
double total = myList.Where(item => item.Name == "Eggs").Sum(item => item.Amount);
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Node / Express: EADDRINUSE, Address already in use - Kill server
... process crashes or is killed. It is only called when the event loop ends, and since server.close() sort of ends the event loop (it still has to wait for currently running stacks here and there) it makes no sense to put that inside the exit event...
On crash, do process.on('uncaughtException', ..) ...
Add a column to a table, if it does not already exist
... sys.columns
WHERE object_id = OBJECT_ID(N'[dbo].[Person]')
AND name = 'ColumnName'
)
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How to remove a lua table entry by its key?
...removing an item in the hashmap portion of a table. What you're doing is standard. However, I'd recommend not overriding table.remove() - for the array portion of a table, the default table.remove() functionality includes renumbering the indices, which your override would not do. If you do want to a...
Use of 'use utf8;' gives me 'Wide character in print'
...se UTF8, then it will interpret those three bytes as your single character and that is what is displayed.
If we add in the utf8 module, things are different. In this case, Perl interprets your string as just two characters.
$ perl -Mutf8 -E 'say join ":", map { ord } split //, "鸡\n";'
40481:10
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How does a ArrayList's contains() method evaluate objects?
Say I create one object and add it to my ArrayList . If I then create another object with exactly the same constructor input, will the contains() method evaluate the two objects to be the same? Assume the constructor doesn't do anything funny with the input, and the variables stored in both objec...
How to enable Heap updates on my android client
Under DDMS , there is a HEAP tab, and then I click my android application under 'Devices'.
But it said:
2 Answers
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What's the point of g++ -Wreorder?
...hat somebody might see the list of member initialisers in the constructor, and think that they're executed in that order (j first, then i). They are not, they are executed in the order the members are defined in the class.
Suppose you wrote A(): j(0), i(j) {}. Somebody might read that, and think th...
How do I convert a string to a double in Python?
...float(x)
2342.3400000000001
There you go. Use float (which behaves like and has the same precision as a C,C++, or Java double).
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How to select following sibling/xml tag using xpath
I have an HTML file (from Newegg) and their HTML is organized like below. All of the data in their specifications table is ' desc ' while the titles of each section are in ' name. ' Below are two examples of data from Newegg pages.
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